(POM) Partial oxidation of methanol over a Pt/Al2O3 catalyst with low Pt content is studied where the influences of the (GHSV) gas hourly space velocity and oxygen-to-methanol molar ratio (O2/C) on the gas formation, reaction temperature, and methanol conversion are evaluated. POM operations under cold start and preheating are also examined. The results indicate that an increase in GHSV significantly lowers POM performance. Nevertheless, over 50% of methanol is consumed when the GHSV is as high as 20,000 h−1. The maximum H2 and CO concentrations are located at O2/C = 0.7, yielding the optimum O2/C ratio for POM. Compared to POM with cold start operation, preheating the catalyst bed at 150 °C obviously intensifies POM performance, and 100% of methanol conversion is achieved at O2/C ≥ 0.6. This reveals that the Pt/Al2O3 catalyst with low Pt content can be used to trigger POM for H2 production. The methanol reaction under the combination of the Pt/Al2O3 catalyst and a Cu/ZnO/Al2O3 catalyst for triggering POM followed by the methanol steam reforming is also investigated. The reaction temperature under the two-stage reaction is lower than that under POM alone, but the methanol conversion and H2 production in the former are improved. This improvement is especially pronounced at high GHSVs.